What makes a replacement window qualified to be ENERGY STAR Rated?

You might have noticed that many replacement window companies install ENERGY STAR-rated windows and doors but you might not know exactly what that means.  Here are some things you should know about Energy Star-qualified windows and doors.

  1. The windows or doors are manufactured by an ENERGY STAR Partner – An ENERGY STAR Partner must be committed to manufacturing windows that have earned the ENERGY STAR label.
  2. The windows are independently tested, certified, and verified by the NFRC (National Fenestration Council – The NFRC helps homeowners to identify the performance of replacement windows and doors with certified ratings and labeling. Below are the performance ratings to look for (find the definitions of each rating below here):
    1. U-Factor
    2. Solar Heat Gain Coefficient (SHGC)
    3. Air Leakage (AL)
    4. Visible Transmittance (VT)
    5. Condensation Resistance
  3. The replacement windows and doors must meet the NFRC ratings listed above to meet the strict energy efficiency guidelines set by the US Environmental Protection Agency (EPA).

Features of an ENERGY STAR-Rated Window

Technology for everything has become more advanced, including replacement windows.  Upgrades that make a window more energy efficient include:

  • Frame Materials – The frame material affects the heat transfer and the insulation.
  • Multiple Panes – Energy Star recommends two panes of glass to allow space between the panes for air or gas to increase energy efficiency, sound reduction, and increased impact resistance.
  • Low-E Glass – Glass coatings reflect infrared light which helps keep heat inside in the winter and outside in the summer.  This coating also helps protect furniture and finishings inside of your home from fading in the sunlight.
  • Gas Fills – Gasses that are commonly used to fill the space between panes of glass include either Argon or Krypton.
  • Warm Edge Spacers – Spacers are used between the panes of glass to reduce heat transfer through the window.